Abstract des Autors

The present study was designed to test if both the intensity and duration of the 45-min Square-Wave Endurance Exercise Test (SWEET) would produce changes in serum enzyme activities. Nine men, four sedentary (S) and five athletes (A), performed VO2 max and SWEET, at their Maximal Intensity of Endurance (MIE45). Arterial blood was sampled at rest (R), exercise (Ex) and during recovery for measurements of levels of Haemoglobin (Hb), Haemotokrit (Hct), pH and seven serum enzymes: Creatine (CPK), Hexose-phosphate isomerase (PHI), Aldolase (ALD), Lactate dehydrogenase (LDH), Malate dehydrogenase (MDH), Aspartate amino-transferase (ASAT or GOT), and Alanine aminotransferase (ALAT or GPT). Five enzymes increased significantly during exercise (MIE45), the delta (Ex-R/R) increases were as follows: PHI (72 ), MDH (28 ), LDH (21 ), CPK (17 ), and GOT (13.5 ), whilst only a 10 increase was observed for Hct and Hb and there was no significant change in the arterial pH. A difference between sedentary and athletes subjects was found at rest and exercise (delta = A-S/S) for CPK (R = 222 ; Ex = 235 ), GOT (R = 90 ; Ex = 75 ) and ALD (R = 99 ; Ex = 54 ). These results suggest that the MIE45 seems to require great muscular effort.